Passivated Single-Crystalline CH 3 NH 3 PbI 3 Nanowire Photodetector with High Detectivity and Polarization Sensitivity

• Published in: Nano letters Vol. 16; no. 12; pp. 7446 - 7454
• Main Authors: Gao, Liang, Zeng, Kai, Guo, Jingshu, Ge, Cong, Du, Jing, Zhao, Yang, Chen, Chao, Deng, Hui, He, Yisu, Song, Haisheng, Niu, Guangda, Tang, Jiang
• Format: Journal Article
• Language: English
• Published: United States 14.12.2016
• Subjects: polarization sensitivity; passivation; Single-crystalline CH3NH3PbI3 nanowire; high detectivity
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.6b03119

Photodetectors convert light signals into current or voltage outputs and are widely used for imaging, sensing, and spectroscopy. Perovskite-based photodetectors have shown high sensitivity and fast response due to the unprecedented low recombination loss in this solution processed semiconductor. Among various types of CH NH PbI morphology (film, single crystal, nanowire), single-crystalline CH NH PbI nanowires are particularly interesting for photodetection because of their reduced grain boundary, morphological anisotropy, and excellent mechanical flexibility. The concomitant disadvantage associated with the CH NH PbI nanowire photodetectors is their large surface area, which catalyzes carrier recombination and material decomposition, thus significantly degrading device performance and stability. Here we solved this key problem by introducing oleic acid soaking to passivate surface defects of CH NH PbI nanowires, which leads to a device with much improved stability and unprecedented sensitivity (measured detectivity of 2 × 10 Jones). By taking advantage of their one-dimensional geometry, we also showcased, for the first time, the linear dichroic photodetection of our CH NH PbI nanowire photodetector.